#!/home/luyanfei/.local/bin/checkio --domain=py run correct-sentence

# https://py.checkio.org/mission/correct-sentence/

# For the input of your function, you will be given one sentence. You have to return a corrected version, that starts with a capital letter and ends with a period (dot).
# 
# Pay attention to the fact that not all of the fixes are necessary. If a sentence already ends with a period (dot), then adding another one will be a mistake.
# 
# Input:A string.
# 
# Output:A string.
# 
# Precondition:No leading and trailing spaces, text contains only spaces, a-z A-Z , and .
# 
# 
# END_DESC

def correct_sentence(text: str) -> str:
    """
        returns a corrected sentence which starts with a capital letter
        and ends with a dot.
    """
    # your code here
    first, *middle, last = text
    return '{0}{1}{2}'.format(first.upper(), ''.join(middle), last if last == '.' else last + '.')


if __name__ == '__main__':
    print("Example:")
    print(correct_sentence("greetings, friends"))
    
    # These "asserts" are used for self-checking and not for an auto-testing
    assert correct_sentence("greetings, friends") == "Greetings, friends."
    assert correct_sentence("Greetings, friends") == "Greetings, friends."
    assert correct_sentence("Greetings, friends.") == "Greetings, friends."
    assert correct_sentence("hi") == "Hi."
    assert correct_sentence("welcome to New York") == "Welcome to New York."
    
    print("Coding complete? Click 'Check' to earn cool rewards!")
